Access control devices for persons and devices for counting persons designed as turnstiles are known from the prior art. They comprise one, two or three barrier arms which are connected in a torque-proof manner to a shaft which can be driven by an electric motor, wherein the angles between the longitudinal axes of the barrier arms are predefined by the torque-proof connection.
In the case of access control systems for persons designed as turnstiles, when a valid access authorization is read by means of a reading device, such a turnstile is transferred from a locking position into a release position by rotation of the shaft to which the barrier arms are connected in a torque-proof manner. In the case of devices for counting persons designed a turnstiles, when a person is detected in the passage, which can be accomplished by means of suitable sensors, for example, light sensors, light curtains, radar sensors etc. the shaft to which the barrier arms are connected in a torque-proof manner is transferred from a looking position into a release position. After each passage, the value of a counter assigned to the direction of passage is increased by 1.
In the case of turnstiles with three barrier arms, as a result of the fixed angle between the barrier arms the comfort during walking through is adversely affected since, for example, luggage or pushchairs must be raised above one of the three barrier arms. Since the angle between the longitudinal axes of two neighbouring barrier arms is usually 120°, in the addition the entire passage cannot be released since one barrier arm always projects into the passage. However, turnstiles with three barrier arms have the advantage that they ensure a sufficient channelling and separation effect since one person is always located between two barrier arms when passing through.
Furthermore, turnstiles with two barrier arms are known which are connected in a torque-proof manner to a shaft which can be driven by an electric motor, which however cannot eliminate the afore-mentioned disadvantages of turnstiles comprising three barrier arms. On the contrary, a secure separation is adversely affected. Furthermore, turnstiles with one barrier arm are known which however in order to ensure separation, are moved rapidly in order to release the passage on the one hand and ensure separation on the other hand, with the result that the risk of injury for persons passing through is increased. Furthermore the wear as a result of the high rotational speed of the mass of the single barrier arm is disadvantageously increased; the high rotational speed is caused by the fact that the barrier arm must be turned through 360 degrees per passage.
In addition, the turnstiles with two or three barrier arms known from the prior art have the disadvantage that in the case of an emergency or when the system is to be put out of operation, the entire passage cannot be released.